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electroman2000
Apprentece
Malta
5 Posts |
 Posted - Oct 26 2005 : 3:27:53 PM
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quote:
well the thing is i do not think that you are understanding how it works,the transformer is the heart that steps up the voltage depending on its specs,so if you use a 220v transformer you will have 220v out,if you use a 110 you will have a 110 and if you use a 60v transformer you will get 60v! it all depends on what transformer you use.
Edited by - electroman2000 on Oct 26 2005 3:30:18 PM |
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thewind
New Member
2 Posts |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Nov 07 2005 : 7:43:30 PM
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What are you going to power from the inverter's 120VAC that uses only 0.6W? A common little night-light draws 10 times more.
That circuit has its capacitors backwards and the transistors will have their absolute max reverse base-emitter voltage rating exceeded.
Hey! I saw that circuit before. It is exactly the same as the faulty inverter design that we have been taling about on all these pages.
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thewind
New Member
2 Posts |
Posted - Nov 07 2005 : 10:26:00 PM
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quote:
What are you going to power from the inverter's 120VAC that uses only 0.6W? A common little night-light draws 10 times more.
That circuit has its capacitors backwards and the transistors will have their absolute max reverse base-emitter voltage rating exceeded.
Hey! I saw that circuit before. It is exactly the same as the faulty inverter design that we have been taling about on all these pages.
i will be using a car-battery as my input, and the output will be used for a gaming device power supply unit. it consumes 120VAC 12W 60Hz
i made a mistake in the first post.
so this is a "faulty inverter" >_< Ouch.....
please help? what's wrong with it?
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Nov 07 2005 : 11:30:45 PM
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I have said what's wrong with this faulty inverter design in my previous reply to you and a few times on nearly every page of this 14 pages thread!
In this thread I even posted a 500W inverter that I helped fix and it works very well.
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cat
Apprentece
Philippines
15 Posts |
Posted - Nov 14 2005 : 06:14:17 AM
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quote:
Hi I am new hear. I have 2 questions 1) what i need is to make an inverter that puts out between 3000 watts to 10,000 watts with about 30 -70 amps (needs to be able to run power tools , 1000 watt lights, 2" sump pump and a copus(air mover) sometimes at the same time. I don't have any idea on how to design the circuit (about all i know is how to solder well Ha Ha ) I do a lot of small electronic modding ( PS2 xbox stufflike that. I have 2 Vector max 3000 watt inverters 1 that works a little and 1 that fried . I have been studying them but i am man to admit that they are a little above me but I am learning. If there is any one who can designe and maybe hold my hand a bit I would be in ther debt. 2) Now this is off subject but does anyone know how i might be able to build a circuit that would let me decode the channels on my TV. Let me explain I don't want to steal cable I only want to be able to watch what I pay for in one room on TV in the other without renting another box from the cable company. I would not mind it if they were reasonable with the price but an extra 29$ a month and 70$ to bring it to my house and hook it up is nuts. all i know is that the channels I pay for in the living room with the converter box show up in the bedroom on my cable ready TV but they are scrambled but the sound is good . Can anyone help or send me to a fourm dedicated to the subject. thanks Slipknots
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Nov 14 2005 : 10:04:35 AM
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A big 12V car battery can provide 450W for about 4 hours. Therefore you would need more than 22 batteries to provide 10,000W.
Making a 450W inverter would be very difficult for you. A 10,000W inverter would be .....
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Kiz1
New Member
Nigeria
4 Posts |
Posted - Nov 23 2005 : 07:30:39 AM
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quote:
(1) corncerning the inverter, can i use a 220v transformer in order to have output of 220vAC, and it has three Dc output wires(secondary side).
(2) The 2N3055 transistor i got was a metal-case type which has only two pins. Now i tested for the base and got that, but how do i know the emitter and collector? Are they both in the other pin? Please try to reply soonestly, i want to finish this project before the end of this month(November 2005). Thanks.
I wold use something smaller but not too small, not 2N2222. Something with 1A collector current at least.
As for resistors, I would think that as base current will be about 100 times less, you can try to increase R3,R4 maybe to 10K or more and get rid of tantalums. Try 1uF ceramics or film caps..
But that is only my guess, remember that! No responsibility on my part... use it on your own risk :))
Handel |
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Kiz1
New Member
Nigeria
4 Posts |
Posted - Nov 23 2005 : 07:34:37 AM
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quote:
(1) corncerning the inverter, can i use a 220v transformer in order to have output of 220vAC, and it has three Dc output wires(secondary side).
(2) The 2N3055 transistor i got was a metal-case type which has only two pins. Now i tested for the base and got that, but how do i know the emitter and collector? Are they both in the other pin? Please try to reply soonestly, i want to finish this project before the end of this month(November 2005). Thanks.
I wold use something smaller but not too small, not 2N2222. Something with 1A collector current at least.
As for resistors, I would think that as base current will be about 100 times less, you can try to increase R3,R4 maybe to 10K or more and get rid of tantalums. Try 1uF ceramics or film caps..
But that is only my guess, remember that! No responsibility on my part... use it on your own risk :))
Handel |
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Kiz1
New Member
Nigeria
4 Posts |
Posted - Nov 23 2005 : 07:36:19 AM
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quote:
(1) corncerning the inverter, can i use a 220v transformer in order to have output of 220vAC, and it has three Dc output wires(secondary side).
(2) The 2N3055 transistor i got was a metal-case type which has only two pins. Now i tested for the base and got that, but how do i know the emitter and collector? Are they both in the other pin? Please try to reply soonestly, i want to finish this project before the end of this month(November 2005). Thanks.
I wold use something smaller but not too small, not 2N2222. Something with 1A collector current at least.
As for resistors, I would think that as base current will be about 100 times less, you can try to increase R3,R4 maybe to 10K or more and get rid of tantalums. Try 1uF ceramics or film caps..
But that is only my guess, remember that! No responsibility on my part... use it on your own risk :))
Handel |
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Kiz1
New Member
Nigeria
4 Posts |
Posted - Nov 23 2005 : 08:23:16 AM
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quote:
I could not get the HEP 154 silicon diode, can you give me the substitute? can i use IN4007 as substitute? thanks
I do not think 60 V is not enough.. on that side of transformer you have only 12V of power, and diodes should protect from flyback voltage.. just a comment :)
Handel |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Nov 23 2005 : 08:27:49 AM
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Kiz,
1) Instead of guessing about pins for transistors, look at the labelled pic on the datasheet. www.datasheetarchive.com .
2) This project is too simple to operate properly. It needs Mosfets or paralleled output transistors and driver transistors to work.
To have a 100W output then the transistors must conduct 10A each from the battery, plus another 1A for R1 and R2. Therefore the current in the transistors is 11A each.
Resistors R3 and R4 provide only about 60mA of base current so the minimum current gain of the transistors must be 11A/60mA= 183. The current gain of power transistors drops at high collector current and the 2N3055 doesn't even have its current gain rated at 11A. Its minimum gain at 10A is only 5.0 and at such a high current it saturates with up to 4V across it.
3) You can try 1A power transistors to have an output of only 10W. But they and the capacitors will blow-up because the circuit causes their base-emitter reverse voltage to far exceed their absolute max rating, causing the junction to avalanch with very high current.
It takes a lot of power for one transistor to drive a high current into the other transistor that has avalanch breakdown. That power is deducted from the project's output power.
Edited by - audioguru on Nov 23 2005 08:36:45 AM |
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tim
Mad Scientist
198 Posts |
Posted - Nov 24 2005 : 6:46:51 PM
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hey aaron do you know the minimum voltage to drive the gates of 34 paralled mosfet transistors 200v 18 amp
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Nov 24 2005 : 8:21:08 PM
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Hi Tim,
If you have a 100V or 200V supply, then why do you need an inverter?
You don't need a 200V-rated Mosfet in an inverter powered from only 12V.
Mosfets are much more efficient than old transistors in inverter circuits and their gate voltage requirement is shown on their datasheets. Most Mosfets need 10V on their gate for them to meet their current spec. Some Mosfets need only a few volts.
Mosfets have a very high gate capacitance and paralleling so many would require a huge current drive to the gates to quickly charge the capacitance. If the drive current is too low then the Mosfets will melt due to the long-duration slew-rate.
Assuming that the Mosfets are switching only half their rated current of 18A which is very low for modern Mosfets, 34 of them would cause a 306A current from a 12V battery that might cause it to blow-up, if it even has the ability to supply so much current. Wires the size of your thumb!
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tim
Mad Scientist
198 Posts |
Posted - Nov 24 2005 : 8:33:20 PM
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this circuit is for my electric truck and it uses 120 dc 400 amps and yes i use 2 gauge welding cable. this is a controller that has 34 mosfets. i bought the controller burned up but im making a new board caps mosfets and resistors but im going to use a 24 v 80 controller but only the pulse width modulater circuit to drive the mosfet gates.
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12/120V inverter again
